"Widespread power outages, mismanagement of the country's oil industry, and U.S. sanctions directed at Venezuela's energy sector and PdVSA have all contributed to the recent declines," a report from EIA Monday read.

The report tracks with a longer-term decline in Venezuela's state-owned oil sector. In 2016 70 oil rigs were operating there, compared to 24 in the first three months of this year.

"EIA expects Venezuela's crude oil production to continue decreasing in 2019, and declines may accelerate as sanctions-related deadlines pass," the report read.

Gulf Coast refineries have long relied on Venezuelan crude to produce gasoline and other fuels but in recent years have been shifting to other suppliers.

EIA said the decline in Venezuelan production "will have limited effects" on U.S. refineries, noting U.S. imports of Venezuelan crude averaged 505,000 barrels a day last year, the lowest level since 1989.